Other Asian, Australian and South Pacific Frequent Flyer Programs - EVA SEA-TPE -- is the 74E *really* being used?

A couple of threads here are leaving me confused about what equipment is being used for SEA-TPE and whether the 74E is actually being substituted in and used recently.

EVAs schedule shows that this week, they are changing from 777 to 744. There's been some speculation that this could allow for more easy swap-in of the 74E.

Then someone claimed that 2 flights within the past few weeks were flown on a "747B" -- I am not sure what that means, but it would conflict with the published schedules, which show 777 being used until this week.

Does anyone know for sure what specific aircraft EVA has been using on SEA recently? And whether they do in fact substitute in the 74E either regularly or from time to time? I had thought we had seen the last of the 74E in SEA and was not aware of EVA substituting it in over the past couple of years.

Over the last year plus, every time I have taken the SEA-TPE flight, I have either been on the 77W or 74W, not the 74E. The 74E seems to only make its rare North American appearances at SFO, and even then there are usually other flights the same day with the 77W.

Yeah, I believe the 74E is never used in SEA.

I am wondering if anyone has any hard evidence that a 74E sometimes get subbed in, because some recent posts in other threads seem to imply that it might be happening.